[llvm] [SelectionDAG] Introducing a new ISD::POISON SDNode to represent the poison value in the IR. (PR #135056)

[Jakub Kuderski via llvm-commits]

https://github.com/kuhar commented:

This fixes the RISC-V crash we observed with the first version of the patch. Thanks for taking care of this!

https://github.com/llvm/llvm-project/pull/135056